There is an ore from two layers with a copper grade of 18% and 26%. How many tons of ore with a 26%

There is an ore from two layers with a copper grade of 18% and 26%. How many tons of ore with a 26% copper grade should be taken to be obtained by mixing it with an ore containing 18% copper 20 tons of ore with a 20% copper grade.

Let’s find what part of the ore 18% is from 20%:

20:18 = 1.11 part.

Let us find what part of the ore 26% is from 20%:

20: 26 = 0.77 part.

Let’s find how many parts in total:

1.11 + 0.77 = 1.88 parts.

Let’s find how many tons of ore with a total mass of 20 tons are contained in one part:

20: 1.88 = 10.6 t.

Let’s find how much ore with 26% copper grade should be in 20 tons of ore with 20% copper grade:

0.77 * 10.6 = 8.19t.

Answer: 20 tonnes of ore with 20% copper grade should contain 8.19 tonnes of ore with 26% copper grade.